1967 3 HP lighttwin dies when accelerated

[hdman97]

Would think there is a problem with the High speed,but this has a fixed high speed.
Took carb all apart again, all clean, all open offorices.
Engine starts, low speed set about 1 1/2 out.
If lever is pushed to fast engine dies,tried adjusting low speed no change.
Had running the other day,now this
I could pull the flywheel again but The points were at .20 new,and the coils looked new also.
Any thoughts? thanks Timing????

 

[nwcove]

Re: 1967 3 HP lighttwin dies when accelerated

will it run for any length of time at low speed?

 

[hdman97]

Re: 1967 3 HP lighttwin dies when accelerated

will it run for any length of time at low speed?

Yes it will .Till I try and speed it up.

 

[nwcove]

Re: 1967 3 HP lighttwin dies when accelerated

check the filter in the tank...if its still there!. sounds like it could be partially plugged. ( just a starting point for trouble shooting)

 

[F_R]

Re: 1967 3 HP lighttwin dies when accelerated

Almost always caused by a dirty high speed jet (orifice plug). It must be absolutely CLEAN without a hint of any dirt, gum, or varnish in it. But don't be jamming wires and drills and stuff through it. Too big is as bad as too small.

But could be caused by insufficient flow from the gas tank (partially clogged fuel filter in tank)

 

[hdman97]

Re: 1967 3 HP lighttwin dies when accelerated

Thanks guys ,I did check those things already,but will check again.Good flow to carb.
What is a "link and synch" adjustment?? I noted someone refering to that on another post
The last time I tried it I had it running for about 10 min with the lever at mid way.
As soon as I tried to turn it up by sliding it to the right about an inch it died.Could not even save it by turning it down quick.

 

[F_R]

Re: 1967 3 HP lighttwin dies when accelerated

Not much to link and sync on that motor. The carb throttle must start to open when aligned with a mark on the brass cam.

I say again, your symptoms are that of a dirty high speed jet. I'll believe I'm wrong when you find otherwise.

 

[hdman97]

Re: 1967 3 HP lighttwin dies when accelerated

I say again, your symptoms are that of a dirty high speed jet. I'll believe I'm wrong when you find otherwise.[/QUOTE]

I would love to agree... LOL
It is a fixed jet on this motor,and I did run a small wire thru it didn't drill it out or anything.This carb almost looks to be new old stock.
Not knowing the history , wonder if its for this engine?
Will look at it again tomorrow.

 

[hdman97]

Re: 1967 3 HP lighttwin dies when accelerated

Well went thru the carb again ..... Problem still the same.
I thought it may be a problem with the float,thinking it isnt keeping up with the demand for fuel.
Will see if there is a after market one out there.
Still open for suggestions.

 

[nwcove]

Re: 1967 3 HP lighttwin dies when accelerated

I say again, your symptoms are that of a dirty high speed jet. I'll believe I'm wrong when you find otherwise.

"I would love to agree... LOL
It is a fixed jet on this motor,and I did run a small wire thru it didn't drill it out or anything.This carb almost looks to be new old stock.
Not knowing the history , wonder if its for this engine?"

dont run a drill through the high speed jet. but at least soak the bowl in carb cleaner, run a piece of wire through it, blow it out, and repeat. thats the lowest spot in the carb and it tends to gather crud....which will happen very quickly if the filter in the tank has been removed by a po.

 

[diveman05]

Re: 1967 3 HP lighttwin dies when accelerated

Well went thru the carb again ..... Problem still the same.
I thought it may be a problem with the float,thinking it isnt keeping up with the demand for fuel.
Will see if there is a after market one out there.
Still open for suggestions.

i have a 55 hp engine with the same problem, i took it to my local small engine guy and turns out my engine is loosing spark... he has no idea why though, new ignition, spark plugs, and points all look good. Are you getting spark and does anyone have any ideas?

 

[hdman97]

Re: 1967 3 HP lighttwin dies when accelerated

dont run a drill through the high speed jet. but at least soak the bowl in carb cleaner, run a piece of wire through it, blow it out, and repeat. thats the lowest spot in the carb and it tends to gather crud....which will happen very quickly if the filter in the tank has been removed by a po.[/QUOTE]

It is very clean around the fixed high speed jet.
I even looked under a magify lamp.
No filter in the tank,but there is a new inline filter on fuel line.
What do you think of the float as a suspect?
Had it running slow for about 15 mins. today,was able to go up a little faster and when it wanted to kill
was able to save it by backing down.
Will keep at it and post back findings.
This ain't my first rodeo,but it sure isn't been easy.Which it should be, this is a very simple engine!
Yeah right

 

[hdman97]

Re: 1967 3 HP lighttwin dies when accelerated

FIXED!!!

Was able to work on it today as the temp droped its was 106 yesterday,too warm for me ,and 82 or so today.
Removed the carb when thru it all again, high speed jet,etc, all looked good.Had another float from a johnson 5.5hp,change it out along with the pin that holds it and she ran great.
I can't say that I see anything that different with the float but it seems to have fixed the problem.
Will be looking into a replacement after market float as this is one of those cork floats.
Thanks guys!!

FIX WAS MAKING A SILENCER THAT WAS MISSING!